every two persons shakes hands with each other in a party & the total number of hand shakes is 66.the number of guests in the party is
ans: 12.
intermediate(ipc)course (no) (1460 Points)
08 October 2011every two persons shakes hands with each other in a party & the total number of hand shakes is 66.the number of guests in the party is
ans: 12.
CA Sahil Singla..
(Service Tax )
(3746 Points)
Replied 08 October 2011
Let no. of Total persons at party = x
This is a porblem on combination bcoz each person will shake hand with other one. Suppose two of them are A & B. Here if we apply permutations then there will be included a case in which A will shake hand with B & B will shake hand with A, which is not possible & irrelevant. So, here we will apply combination as follows-
xC2 = 66
this implies (x(x-1))/2= 66
implies x= 12